Government spending will make up a larger chunk of the UK economy than it does in Germany by next year, fuelling claims that Gordon Brown has abandoned the lean Anglo-Saxon economic model in favour of the tax-and-spend habits of his eurozone neighbours.

Germany, for many years the sick man of Europe, is often seen as the epitome of the sclerotic, big-government European model - but projections from the Paris-based Organisation for Economic Co-operation and Development show the size of the state in Britain expanding to 45.7 per cent of GDP in 2007, against 45 per cent in Germany.

'While Gordon Brown is busy lecturing continental European countries about how they need to change, his taxes and excessive regulation are taking us in the wrong direction, making us less competitive and more similar to our European rivals,' said George Osborne, the shadow Chancellor. 'Why doesn't he practise what he preaches?'

Holger Schmieding, chief European economist at Bank of America, said the 'fiscal convergence' between Britain and Germany marked in the OECD figures showed that Brown's policies have 'put Britain firmly in the European camp, and moved it away from the US'. He believes the larger state sector will put the brakes on the UK economy in the years ahead.

While Germany has been under pressure to squeeze public spending to comply with the rules of euro-membership, Brown has deliberately turned on the taps to reverse decades of underinvestment in the UK's creaking infrastructure. The Chancellor was criticised by the European Commission in Brussels last week for running a bigger budget deficit than the euro-rules would allow.

The OECD shows the total tax-burden in the UK rising, from 40.7 per cent in 1999, to 42.4 per cent this year, overtaking Germany, where the tax-take has fallen over the same period from 46.7 per cent of GDP, to 42.1 per cent.

Since 1993, the UK has grown 50 per cent faster than the eurozone; but with Germany poised for a long-awaited recovery, economists say the UK's long phase as Europe's star performer could be about to end.

A Treasury spokesman said: 'If you look at the average family in the UK, or the average business, what you find is, they're starting from a better position than their German counterparts, and they're being taxed less.'

He added that government spending as a proportion of GDP was still well below the levels of the Eighties, before the wave of privatisations in the Thatcher-era began rolling back the state.

The Treasury's current fiscal plans, published in Brown's December Pre-Budget Report, show the spending glut coming to an end next year, with a tough spending round due in the summer.

The Conservatives, meanwhile, have pledged to 'share the proceeds of growth', handing cash back to the voters in tax cuts as the economy expands, and shrinking the size of the state.